Map generation apparatus

ABSTRACT

A map generation apparatus including a microprocessor. The microprocessor is configured to perform recognizing another vehicle traveling on an opposite lane opposite to a current lane on which a subject vehicle travels, acquiring an information of an external situation around the other vehicle in a route matching section when the other vehicle is recognized, the information of the external situation being obtained by the other vehicle traveling on the opposite lane, the route matching section being a section in which a driving route of the subject vehicle and a driving route of the other vehicle match in a driving route including the current lane and the opposite lane, and generating a map for the opposite lane in the route matching section, based on the information of the external situation.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2021-028502 filed on Feb. 25, 2021, thecontent of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to a map generation apparatus configured togenerate a map around a subject vehicle.

Description of the Related Art

Conventionally, there is a known apparatus in which white lines of alane and a parking lot frame are recognized using an image captured by acamera mounted on a vehicle, and the recognition results of the whitelines are used for vehicle driving control and parking support. Such anapparatus is described, for example, in Japanese Unexamined PatentPublication No. 2014-104853 (JP2014-104853A). In the apparatus disclosedin JP2014-104853A, edge points at which a change in luminance in thecaptured image is equal to or greater than a threshold is extracted, andthe white lines are recognized based on the edge points.

In the apparatus described in JP2014-104853A, a white line is recognizedfor a lane on which a subject vehicle has actually traveled. Therefore,in order to generate a map including position information of the whiteline, it is necessary for the subject vehicle to actually travel in eachlane, and it is difficult to efficiently generate the map.

SUMMARY OF THE INVENTION

An aspect of the present invention is a map generation apparatusincluding an electronic control unit including a microprocessor and amemory connected to the microprocessor. The microprocessor is configuredto perform recognizing another vehicle traveling on an opposite laneopposite to a current lane on which a subject vehicle travels, acquiringan information of an external situation around the other vehicle in aroute matching section when the other vehicle is recognized, theinformation of the external situation being obtained by the othervehicle traveling on the opposite lane, the route matching section beinga section in which a driving route of the subject vehicle and a drivingroute of the other vehicle match in a driving route including thecurrent lane and the opposite lane, and generating a map for theopposite lane in the route matching section, based on the information ofthe external situation.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features, and advantages of the present invention willbecome clearer from the following description of embodiments in relationto the attached drawings, in which:

FIG. 1 is a block diagram schematically illustrating an overallconfiguration of a vehicle control system having a map generationapparatus according to an embodiment of the present invention;

FIG. 2 is a view illustrating an example of a traveling scene to whichthe map generation apparatus according to the embodiment of theinvention is applied;

FIG. 3 is a block diagram illustrating a configuration of a substantialpart of the map generation apparatus according to the embodiment of theinvention;

FIG. 4A is a view illustrating another example of a traveling scene towhich the map generation apparatus according to the embodiment of theinvention is applied;

FIG. 4B is a view illustrating a further other example of a travelingscene to which the map generation apparatus according to the embodimentof the invention is applied; and

FIG. 5 is a flowchart illustrating an example of processing executed bya controller in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment of the present invention is explained withreference to FIGS. 1 to 5. A map generation apparatus according to anembodiment of the invention is applied to a vehicle having aself-driving capability, i.e., a self-driving vehicle, for example. Theself-driving vehicle having the map generation apparatus may besometimes called “subject vehicle” to differentiate it from othervehicles. The subject vehicle is an engine vehicle having an internalcombustion engine (engine) as a travel drive source, electric vehiclehaving a travel motor as the travel drive source, or hybrid vehiclehaving both of the engine and the travel motor as the travel drivesource. The subject vehicle can travel not only in a self-drive mode inwhich a driving operation by a driver is unnecessary, but also in amanual drive mode in which the driving operation by the driver isnecessary.

First, the general configuration of the subject vehicle for self-drivingwill be explained. FIG. 1 is a block diagram schematically illustratingan overall configuration of a vehicle control system 100 of the subjectvehicle having the map generation apparatus according to an embodimentof the present invention. As shown in FIG. 1, the vehicle control system100 mainly includes a controller 10, and an external sensor group 1, aninternal sensor group 2, an input/output device 3, a positionmeasurement unit 4, a map database 5, a navigation unit 6, acommunication unit 7 and actuators AC which are communicably connectedwith the controller 10.

The term external sensor group 1 herein is a collective designationencompassing multiple sensors (external sensors) for detecting externalcircumstances constituting subject vehicle ambience data. For example,the external sensor group 1 includes, inter alia, a LIDAR (LightDetection and Ranging) for measuring distance from the subject vehicleto ambient obstacles by measuring scattered light produced by laserlight radiated from the subject vehicle in every direction, a RADAR(Radio Detection and Ranging) for detecting other vehicles and obstaclesaround the subject vehicle by radiating electromagnetic waves anddetecting reflected waves, and a CCD, CMOS or other imagesensor-equipped on-board cameras for imaging subject vehicle ambience(forward, reward and sideways).

The term internal sensor group 2 herein is a collective designationencompassing multiple sensors (internal sensors) for detecting drivingstate of the subject vehicle. For example, the internal sensor group 2includes, inter alia, a vehicle speed sensor for detecting vehicle speedof the subject vehicle, acceleration sensors for detectingforward-rearward direction acceleration and lateral acceleration of thesubject vehicle, respectively, rotational speed sensor for detectingrotational speed of the travel drive source, a yaw rate sensor fordetecting rotation angle speed around a vertical axis passing center ofgravity of the subject vehicle and the like. The internal sensor group 2also includes sensors for detecting driver driving operations in manualdrive mode, including, for example, accelerator pedal operations, brakepedal operations, steering wheel operations and the like.

The term input/output device 3 is used herein as a collectivedesignation encompassing apparatuses receiving instructions input by thedriver and outputting information to the driver. The input/output device3 includes, inter alia, switches which the driver uses to input variousinstructions, a microphone which the driver uses to input voiceinstructions, a display for presenting information to the driver viadisplayed images, and a speaker for presenting information to the driverby voice.

The position measurement unit (GNSS unit) 4 includes a positionmeasurement sensor for receiving signal from positioning satellites tomeasure the location of the subject vehicle. The positioning satellitesare satellites such as GPS satellites and Quasi-Zenith satellite. Theposition measurement unit 4 measures absolute position (latitude,longitude and the like) of the subject vehicle based on signal receivedby the position measurement sensor.

The map database 5 is a unit storing general map data used by thenavigation unit 6 and is, for example, implemented using a magnetic diskor semiconductor element. The map data include road position data androad shape (curvature etc.) data, along with intersection and roadbranch position data. The map data stored in the map database 5 aredifferent from high-accuracy map data stored in a memory unit 12 of thecontroller 10.

The navigation unit 6 retrieves target road routes to destinations inputby the driver and performs guidance along selected target routes.Destination input and target route guidance is performed through theinput/output device 3. Target routes are computed based on currentposition of the subject vehicle measured by the position measurementunit 4 and map data stored in the map database 35. The current positionof the subject vehicle can be measured, using the values detected by theexternal sensor group 1, and on the basis of this current position andhigh-accuracy map data stored in the memory unit 12, target route may becalculated.

The communication unit 7 communicates through networks including theInternet and other wireless communication networks to access servers(not shown in the drawings) to acquire map data, travel historyinformation, traffic data and the like, periodically or at arbitrarytimes. In addition to acquiring travel history information, travelhistory information of the subject vehicle may be transmitted to theserver via the communication unit 7. The networks include not onlypublic wireless communications network, but also closed communicationsnetworks, such as wireless LAN, Wi-Fi and Bluetooth, which areestablished for a predetermined administrative area. Acquired map dataare output to the map database 5 and/or memory unit 12 via thecontroller 10 to update their stored map data.

The actuators AC are actuators for traveling of the subject vehicle. Ifthe travel drive source is the engine, the actuators AC include athrottle actuator for adjusting opening angle of the throttle valve ofthe engine (throttle opening angle). If the travel drive source is thetravel motor, the actuators AC include the travel motor. The actuatorsAC also include a brake actuator for operating a braking device andturning actuator for turning the front wheels FW.

The controller 10 is constituted by an electronic control unit (ECU).More specifically, the controller 10 incorporates a computer including aCPU or other processing unit (a microprocessor) 51 for executing aprocessing in relation to travel control, the memory unit (a memory) 12of RAM, ROM and the like, and an input/output interface or otherperipheral circuits not shown in the drawings. In FIG. 1, the controller10 is integrally configured by consolidating multiplefunction-differentiated ECUs such as an engine control ECU, atransmission control ECU and so on. Optionally, these ECUs can beindividually provided.

The memory unit 12 stores high-accuracy detailed road map data (road mapinformation) for self-driving. The road map information includesinformation on road position, information on road shape (curvature,etc.), information on gradient of the road, information on position ofintersections and branches, information on type and position of divisionline such as white line, information on the number of lanes, informationon width of lane and the position of each lane (center position of laneand boundary line of lane), information on position of landmarks(traffic lights, signs, buildings, etc.) as a mark on the map, andinformation on the road surface profile such as unevennesses of the roadsurface, etc. The map information stored in the memory unit 12 includesmap information (referred to as external map information) acquired fromthe outside of the subject vehicle through the communication unit 7, andmap information (referred to as internal map information) created by thesubject vehicle itself using the detection values of the external sensorgroup 1 or the detection values of the external sensor group 1 and theinternal sensor group 2.

The external map information is, for example, information of a map(called a cloud map) acquired through a cloud server, and the internalmap information is information of a map (called an environmental map)consisting of point cloud data generated by mapping using a techniquesuch as SLAM (Simultaneous Localization and Mapping). The external mapinformation is shared by the subject vehicle and other vehicles, whereasthe internal map information is unique map information of the subjectvehicle (e.g., map information that the subject vehicle has alone). Inan area in which no external map information exists, such as a newlyestablished road, an environmental map is created by the subject vehicleitself. The internal map information may be provided to the server oranother vehicle via the communication unit 7. The memory unit 12 alsostores information such as programs for various controls, and thresholdsused in the programs.

As functional configurations in relation to mainly self-driving, theprocessing unit 11 includes a subject vehicle position recognition unit13, an external environment recognition unit 14, an action plangeneration unit 15, a driving control unit 16, and a map generation unit17.

The subject vehicle position recognition unit 13 recognizes the positionof the subject vehicle (subject vehicle position) on the map based onposition information of the subject vehicle calculated by the positionmeasurement unit 4 and map information stored in the map database 5.Optionally, the subject vehicle position can be recognized using mapinformation stored in the memory unit 12 and ambience data of thesubject vehicle detected by the external sensor group 1, whereby thesubject vehicle position can be recognized with high accuracy. Themovement information (movement direction, movement distance) of thesubject vehicle is calculated based on the detection value of theinternal sensor group 2, thereby it is also possible to recognize theposition of the subject vehicle. Optionally, when the subject vehicleposition can be measured by sensors installed externally on the road orby the roadside, the subject vehicle position can be recognized withhigh accuracy by communicating with such sensors through thecommunication unit 7.

The external environment recognition unit 14 recognizes externalcircumstances around the subject vehicle based on signals from cameras,LIDERs, RADARs and the like of the external sensor group 1. For example,it recognizes position, speed and acceleration of nearby vehicles(forward vehicle or rearward vehicle) driving in the vicinity of thesubject vehicle, position of vehicles stopped or parked in the vicinityof the subject vehicle, and position and state of other objects. Otherobjects include traffic signs, traffic lights, road, buildings,guardrails, power poles, commercial signs, pedestrians, bicycles, andthe like. The other objects (road) also include road division lines(white lines, etc.) and stop lines. Recognized states of other objectsinclude, for example, traffic light color (red, green or yellow) andmoving speed and direction of pedestrians and bicycles. A part of astationary object among other objects, constitutes a landmark serving asan index of position on the map, and the external environmentrecognition unit 14 also recognizes the position and type of thelandmark.

The action plan generation unit 15 generates a driving path (targetpath) of the subject vehicle from present time point to a certain timeahead based on, for example, a target route computed by the navigationunit 6, map information stored in the memory unit 12, subject vehicleposition recognized by the subject vehicle position recognition unit 13,and external circumstances recognized by the external environmentrecognition unit 14. When multiple paths are available on the targetroute as target path candidates, the action plan generation unit 15selects from among them the path that optimally satisfies legalcompliance, safe efficient driving and other criteria, and defines theselected path as the target path. The action plan generation unit 15then generates an action plan matched to the generated target path. Anaction plan is also called “travel plan”. The action plan generationunit 15 generates various kinds of action plans corresponding toovertake traveling for overtaking the forward vehicle, lane-changetraveling to move from one traffic lane to another, following travelingto follow the preceding vehicle, lane-keep traveling to maintain samelane, deceleration or acceleration traveling. When generating a targetpath, the action plan generation unit 15 first decides a drive mode andgenerates the target path in line with the drive mode.

In self-drive mode, the driving control unit 16 controls the actuatorsAC to drive the subject vehicle along target path generated by theaction plan generation unit 15. More specifically, the driving controlunit 16 calculates required driving force for achieving the targetaccelerations of sequential unit times calculated by the action plangeneration unit 15, taking running resistance caused by road gradientand the like into account. And the driving control unit 16feedback-controls the actuators AC to bring actual acceleration detectedby the internal sensor group 2, for example, into coincidence withtarget acceleration. In other words, the driving control unit 16controls the actuators AC so that the subject vehicle travels at targetspeed and target acceleration. On the other hand, in manual drive mode,the driving control unit 16 controls the actuators AC in accordance withdriving instructions by the driver (steering operation and the like)acquired from the internal sensor group 2.

The map generation unit 17 generates the environment map constituted bythree-dimensional point cloud data using detection values detected bythe external sensor group 1 during traveling in the manual drive mode.Specifically, an edge indicating an outline of an object is extractedfrom a camera image acquired by the camera based on luminance and colorinformation for each pixel, and a feature point is extracted using theedge information. The feature point is, for example, an intersection ofthe edges, and corresponds to a road division line, a corner of abuilding, a corner of a road sign, or the like. The map generation unit17 calculates the distance to the extracted feature point andsequentially plots the feature point on the environment map, therebygenerating the environment map around the road on which the subjectvehicle has traveled. The environment map may be generated by extractingthe feature point of an object around the subject vehicle using dataacquired by radar or LIDAR instead of the camera.

The subject vehicle position recognition unit 13 performs subjectvehicle position estimation processing in parallel with map creationprocessing by the map generation unit 17. That is, the position of thesubject vehicle is estimated based on a change in the position of thefeature point over time. The map creation processing and the positionestimation processing are simultaneously performed, for example,according to an algorithm of SLAM using signals from the camera orLIDAR. The map generation unit 17 can generate the environment map notonly when the vehicle travels in the manual drive mode but also when thevehicle travels in the self-drive mode. If the environment map hasalready been generated and stored in the memory unit 12, the mapgeneration unit 17 may update the environment map with a newly obtainedfeature point.

A configuration of a map generation apparatus according to the presentembodiment will be described. FIG. 2 is a diagram illustrating anexample of a driving scene to which the map generation apparatusaccording to the present embodiment is applied, and illustrates a middleof a scene in which a subject vehicle 101 travels from a point A (forexample, home) to a point B (for example, a store) as the destinationwhile generating an environmental map in a manual drive mode. Morespecifically, a scene in which the vehicle travels on a current lane(first lane LN1) defined by left and right division lines L1 and L2 isillustrated. FIG. 2 also illustrates other vehicle 102 traveling on anopposite lane opposite to the current lane, that is, an opposite lane(second lane LN2) defined by left and right division lines L2 and L3.

The division lines L1 to L3 are, for example, solid or broken whitelines. For the subject vehicle 101, the first lane LN1 is an outwardpath to a destination, and the second lane LN2 is a return path at thetime of returning from the destination. The first lane LN1 and thesecond lane LN2 are adjacent to each other. FIG. 2 illustrates anexample in which the outward path and the return path are configured bythe single lanes LN1 and LN2, respectively, but at least one of theoutward path and the return path may be configured by a plurality oflanes.

In FIG. 2, the subject vehicle 101 and other vehicle 102 at a currenttime point T0 are indicated by solid lines, and the subject vehicle 101and other vehicle 102 at a first time point T1 after a lapse of apredetermined time from the current time point T0 and the subjectvehicle 101 and other vehicle 102 at a second time point T2 after alapse of a predetermined time from the first time point T1 are indicatedby dotted lines. The positions of the subject vehicle 101 at the currenttime point T0, the first time point T1, and the second time point T2 arereferred to as a current point P0, a first point P1, and a second pointP2, respectively. At the current point P0, other vehicle 102 is locatedin front of the subject vehicle 101, at the first point P1, the subjectvehicle 101 passes other vehicle 102, and at the second point P2, othervehicle 102 is located behind the subject vehicle 101.

The first lane LN1 and the second lane LN2 extend in parallel to eachother and are located on the same driving route RT. In the driving routeRT, a section from the current point P0 to the first point P1 is asection (referred to as a pre-passing section) ΔL1 before the subjectvehicle 101 and other vehicle 102 approach each other and pass eachother, and a section from the first point P1 to the second point P2 is asection (referred to as a post-passing section) ΔL2 after the subjectvehicle 101 and other vehicle 102 pass each other and the subjectvehicle 101 is away from other vehicle 102.

A camera 1 a is mounted on a front portion of the subject vehicle 101.The camera 1 a has a unique viewing angle θ determined by theperformance of the camera and a maximum detection distance r. An insideof a fan-shaped area AR1 having a radius r and a central angle θcentered on the camera 1 a is a range of an external space detectable bythe camera 1 a, that is, a detectable area AR1. The detectable area AR1includes, for example, a plurality of division lines L1 and L2. Notethat, in a case where a part of the viewing angle of the camera 1 a isblocked by the presence of components disposed around the camera 1 a,the detectable area AR1 may be different from that illustrated in thedrawing.

A camera 102 a similar to that of the subject vehicle 101 is alsomounted on a front portion of other vehicle 102. A detectable area AR2by the camera 102 a is, for example, the same as the detectable areaAR1, and an inside of a fan-shaped range having a radius r and a centralangle θ centered on the camera 102 a is the detectable range. Thedetectable area AR2 includes, for example, a plurality of division linesL2 and L3. That is, in the present embodiment, the detectable area AR1of the camera 1 a of the subject vehicle 101 and the detectable area AR2of the camera 102 a of other vehicle 102 include the same division lineL2 among the division lines L1 to L3. Note that the detectable areas AR1and AR2 are determined not only by the performance of the cameras 1 aand 102 a but also by the vehicle types to which the cameras 1 a and 102a are attached, the attachment positions of the cameras 1 a and 102 a,and the like, and the detectable area AR1 and the detectable area AR2may be different from each other.

In such a driving scene, by extracting edge points from an image of thecamera 1 a acquired while the subject vehicle 101 travels on the currentlane, it is possible to generate an environmental map of the currentlane (first lane LN1) included in the detectable area AR1. That is, thesubject vehicle 101 actually travels on the outward path which is thefirst lane LN1, so that it is possible to obtain an environmental map(outward path map) of the outward path. After traveling on the outwardpath, the subject vehicle 101 actually travels on the return path, whichis the second lane LN2, to obtain a camera image of the return path, sothat it is possible to generate an environmental map (return path map)of the return path.

However, when the environmental map of the return path cannot beobtained until the vehicle actually travels on the return path aftertraveling on the outward path, the number of man-hours required for mapgeneration increases, and map generation cannot be efficientlyperformed. Therefore, in order to enable efficient map generation, thepresent embodiment configures a map generation apparatus as follows.

FIG. 3 is a block diagram illustrating a main configuration of a mapgeneration apparatus 50 according to the present embodiment. The mapgeneration apparatus 50 constitutes a part of a vehicle control system100 in FIG. 1. As illustrated in FIG. 3, the map generation apparatus 50has a controller 10, a camera 1 a, and a sensor 2 a.

The camera 1 a is a monocular camera having an imaging element (imagesensor) such as a CCD or a CMOS, and constitutes a part of the externalsensor group 1 in FIG. 1. The camera 1 a may be a stereo camera. Thecamera 1 a is attached to, for example, a predetermined position in thefront portion of the subject vehicle 101 (FIG. 2), continuously capturesan image of a space in front of the subject vehicle 101, and acquires animage (camera image) of a target object. The target object includes abuilding or a sign around the subject vehicle 101 and a division line(for example, the division lines L1 and L2 in FIG. 2) on a road. Notethat the target object may be detected by a LiDAR or the like instead ofthe camera 1 a or together with the camera 1 a.

The sensor 2 a is a detection part used to calculate a movement amountand a movement direction of the subject vehicle 101. The sensor 2 a is apart of the internal sensor group 2, and includes, for example, avehicle speed sensor and a yaw rate sensor. That is, the controller 10(for example, a subject vehicle position recognition unit 13 in FIG. 1)calculates the movement amount of the subject vehicle 101 by integratinga vehicle speed detected by the vehicle speed sensor, calculates a yawangle by integrating the yaw rate detected by the yaw rate sensor, andestimates a position of the subject vehicle 101 by odometry. Forexample, when the vehicle travels in the manual drive mode, the positionof the subject vehicle is estimated by odometry when the environmentalmap is created. Note that the configuration of the sensor 2 a is notlimited thereto, and the position of the subject vehicle may beestimated using information of other sensor.

The controller 10 in FIG. 3 has a vehicle recognition unit 173, a routedetermination unit 174, and an information acquisition unit 175 inaddition to an action plan generation unit 15 and a map generation unit17, as a functional configuration of a processing unit 11 (FIG. 1). Thevehicle recognition unit 173, the route determination unit 174, and theinformation acquisition unit 175 have a map generation function.Therefore, these units can also be included in the map generation unit17.

The vehicle recognition unit 173 recognizes other vehicle 102 travelingon the opposite lane (second lane LN2), on the basis of the camera imageacquired by the camera 1 a. Other vehicle 102 traveling on the oppositelane includes not only other vehicle 102 before passing which travels infront of the subject vehicle 101 but also other vehicle 102 afterpassing which travels behind the subject vehicle 101. Other vehicle 102may be recognized by a radar, a LiDAR, or the like. The vehiclerecognition unit 173 may recognize other vehicle 102 by acquiringposition information of other vehicle 102 via a communication unit 7.

When other vehicle 102 is recognized by the vehicle recognition unit173, the route determination unit 174 estimates the driving route ofother vehicle 102 on the basis of the camera image. Then, it isdetermined whether or not there is a section (referred to as a routematching section) in which the driving route of the subject vehicle 101and the driving route of other vehicle 102 match in the driving route RTincluding the current lane and the opposite lane. For example, in theexample of FIG. 2, each of the pre-passing section ΔL1 in which thesubject vehicle 101 and other vehicle 102 approach each other and thepost-passing section ΔL2 in which the subject vehicle 101 and othervehicle 102 are separated from each other is the route matching section.

The pre-passing section ΔL1 and the post-passing section ΔL2 can beregarded as the following sections in a state where the subject vehicle101 has moved to the point P1 (FIG. 2). That is, the pre-passing sectionΔL1 is a section in which a route on which the subject vehicle 101 hasalready traveled matches with a route on which other vehicle 102 isscheduled to travel in the future, and the post-passing section ΔL2 is asection in which a route on which the subject vehicle 101 is scheduledto travel in the future matches with a route on which other vehicle 102has already traveled.

The route matching section does not always include the pre-passingsection ΔL1 and the post-passing section ΔL2. FIGS. 4A and 4B arediagrams illustrating an example in which the subject vehicle 101traveling on the current lane (first lane LN1) and other vehicle 102traveling on the opposite lane (second lane LN2) pass each other at anintersection. FIG. 4A illustrates an example in which the subjectvehicle 101 goes straight through an intersection 103, while othervehicle 102 turns left at the intersection 103. In this case, othervehicle 102 does not travel on the route on which the subject vehicle101 has already traveled, and the route matching section is only thepost-passing section ΔL2. On the other hand, FIG. 4B illustrates anexample in which, when the subject vehicle 101 goes straight through theintersection 103, other vehicle 102 enters the intersection 103 andtravels on the second lane LN2. In this case, the subject vehicle 101does not travel on the route on which other vehicle 102 has alreadytraveled, and the route matching section is only the pre-passing sectionΔL1.

Note that, in the route matching section, the subject vehicle 101 andother vehicle 102 do not always pass each other. For example, when thesubject vehicle 101 passes through the intersection 103 after othervehicle 102 turns left at the intersection 103 in FIG. 4A, or when othervehicle 102 enters the intersection 103 after the subject vehicle 101passes through the intersection 103 in FIG. 4B, the passing between thesubject vehicle 101 and other vehicle 102 does not occur. However, evenin this case, there is a section in which the route on which the subjectvehicle 101 travels or has traveled matches with the route on whichother vehicle 102 travels or has traveled, and there is a route matchingsection.

The determination as to whether there is a route matching section ismade for other vehicle 102 recognized by the vehicle recognition unit173. Therefore, other vehicle 102 recognized by the vehicle recognitionunit 173 includes, in addition to other vehicle 102 (FIG. 2) travelingon the opposite lane (second lane LN2) at the current time point T0,other vehicle 102 (FIG. 4A) traveling on the opposite lane at a pasttime point and other vehicle 102 (FIG. 4B) scheduled to travel on theopposite lane at a future time point. That is, even if other vehicle 102does not travel on the opposite lane at the current time point T0, thereis a case where there is a route matching section with the subjectvehicle 101, and all other vehicles 102 having a possibility of having aroute matching section with the subject vehicle 101 are included inother vehicle 102 recognized by the vehicle recognition unit 173.

When it is determined by the route determination unit 174 that there isa route matching section between the subject vehicle 101 and othervehicle 102, the information acquisition unit 175 acquires informationfrom other vehicle 102 via the communication unit 7. That is,information is acquired by inter-vehicle communication. Specifically,information on an external situation around other vehicle 102, such asan image acquired by the camera 102 a of other vehicle 102 in the routematching section, is acquired. The information includes a division line,a lane width, a road shape, a road surface state, constructioninformation, accident information, and the like in the route matchingsection. Instead of the camera 102 a, a signal from a radar, a LiDAR, orthe like mounted on other vehicle 102 may be acquired. Similarly to thesubject vehicle 101, other vehicle 102 may generate the environmentalmap on the basis of the image of the camera 102 a. In this case, theinformation acquisition unit 175 may acquire information of theenvironmental map generated by other vehicle 102.

The map generation unit 17 has an outward path map generation unit 171that generates an environmental map of an outward path (outward pathmap) and a return path map generation unit 172 that generates anenvironmental map of a return path (return path map). At the time oftraveling on the outward path in the manual drive mode, the outward pathmap generation unit 171 extracts feature points of objects around thesubject vehicle 101 on the basis of the camera image acquired by thecamera 1 a, and estimates the subject vehicle position by the sensor 2a, thereby generating the environmental map of the outward path. Thegenerated outward path map is stored in the memory unit 12. The outwardpath map generation unit 171 recognizes the positions of the divisionlines L1 and L2 (FIG. 2A) in the detectable area AR1 of the camera 1 a,and stores the division line information in map information (forexample, internal map information).

At the time of traveling on the outward path in the manual drive mode,the return path map generation unit 172 generates the environmental mapof the return path under a condition that a return path map generationcondition is established. The return path map generation condition isestablished when it is determined by the route determination unit 174that there is a route matching section. On the other hand, when it isdetermined that the return path map generation condition is notestablished at the time of traveling on the outward path in the manualdrive mode, the environmental map of the return path is not generated atthe time of traveling on the outward path. In this case, at the time oftraveling on the return path in the manual drive mode, similarly to theoutward path map generation unit 171, the return path map generationunit 172 extracts feature points of objects around the subject vehicle101 on the basis of the camera image, and estimates the subject vehicleposition by the sensor 2 a, thereby generating the environmental map ofthe return path. The generated return path map is stored in the memoryunit 12.

When the return path map generation condition is established at the timeof traveling on the outward path, the return path map generation unit172 generates the environmental map of the return path on the basis ofthe information acquired by the information acquisition unit 175. Thatis, the return path map is generated on the basis of informationindicating an external situation around other vehicle 102 in the routematching section, specifically, the camera image. As a result, thereturn path map is obtained before the subject vehicle 101 travels onthe return path. The generated return path map is stored in the memoryunit 12. The return path map generation unit 172 recognizes thepositions of the division lines L2 and L3 (FIG. 2A) in the detectablearea AR2 of the camera 102 a, and stores the division line informationin map information (for example, internal map information). Note that,at the time of traveling on the outward path in the manual drive mode,the map generation unit 17 generates the return path map by the returnpath map generation unit 172 while generating the outward path map bythe outward path map generation unit 71. That is, the outward path mapand the return path map are simultaneously generated. After the outwardpath map is generated, the return path map may be generated.

When the subject vehicle 101 travels on the return path in theself-drive mode, the action plan generation unit 15 sets a target routeusing the return path map stored in the memory unit 12. The drivingcontrol unit 16 (FIG. 1) controls an actuator AC so that the subjectvehicle 101 automatically travels along the target route. As a result,even when the subject vehicle 101 travels on the return path for thefirst time, the subject vehicle can travel in the self-drive mode usingthe environmental map of the return path obtained at the time oftraveling on the outward path.

FIG. 5 is a flowchart illustrating an example of processing executed bythe controller 10 of FIG. 3 according to a predetermined program. Theprocessing illustrated in the flowchart is started when the vehicletravels on the first lane LN1 in the manual drive mode, and is repeatedat a predetermined cycle. Note that the processing of FIG. 5 will bedescribed below with reference to FIG. 2.

As illustrated in FIG. 5, first, signals from the camera 1 a and thesensor 2 a are read in S1 (S: processing step). Next, in S2, anenvironmental map at the current point P0 of the current lane (firstlane LN1), that is, an outward path map is generated on the basis of theread signals (camera image or the like). Next, in S3, it is determinedwhether or not other vehicle 102 traveling on the opposite lane (secondlane LN2) is recognized around the subject vehicle 101, on the basis ofthe camera image or the like read in S1. In a case where the result ofdetermination in S3 is YES, the process proceeds to S4, and in a casewhere the result of determination in S3 is NO, the process passes S4 toS6 and proceeds to S7.

In S4, the driving route of other vehicle 102 is estimated on the basisof the camera image and the like read in S1. The estimated driving routeincludes not only a route on which other vehicle 102 currently travelsbut also a route on which other vehicle 102 has traveled in the past anda route on which other vehicle 102 is expected to travel in the future.For example, in the processing at the time point T1 when the subjectvehicle 101 is located at the point P1 in FIG. 2, a driving route (pastroute) from the point P2 to the point P1 of other vehicle 102 and aroute (future route) from the point P2 to the point P0 are included.Further, in S4, it is determined whether or not there is a section inwhich the estimated driving route of other vehicle 102 and the drivingroute of the subject vehicle 101 match, that is, a route matchingsection. In a case where the result of determination in S4 is YES, theprocess proceeds to S5, and in a case where the result of determinationin S4 is NO, the process passes S5 and S6 and proceeds to S7.

In S5, information in the route matching section, specifically,information such as a camera image is acquired from other vehicle 102 byinter-vehicle communication via the communication unit 7. Next, in S6,an environmental map for the opposite lane, that is, a return path mapis generated on the basis of the acquired information (camera image orthe like). Next, in S7, the outward path map generated in S2 and thereturn path map generated in S6 are stored in the memory unit 12, andthe processing ends.

Note that the processing of S5 may be performed every time theprocessing of the flowchart is repeated, but when other vehicle 102 hasa function of storing information, the stored information may becollectively acquired from other vehicle 102 at predetermined timinginstead of being performed every time the processing is repeated. Forexample, until the subject vehicle 101 reaches the first point P1 fromthe point P0 in FIG. 2, the information is not acquired even if othervehicle 102 is recognized, and when the subject vehicle reaches thefirst point P1, information of the post-passing section ΔL2 may becollectively acquired from other vehicle 102. As a result, theprocessing load on the controller 10 can be reduced.

In addition, information may not be acquired when it is determined in S4that there is a route matching section, and information may becollectively acquired when it is determined that the length of the routematching section is a predetermined length or more. As a result, in acase where other vehicle 102 simply crosses the opposite lane, such as acase where other vehicle 102 travels on a road intersecting the currentlane, information is not acquired from other vehicle 102, and it ispossible to prevent acquisition of useless information having a lowutility value for generating the return path map.

The operation of the map generation apparatus 50 according to thepresent embodiment is summarized as follows. As illustrated in FIG. 2,when the subject vehicle 101 travels on the current lane (first laneLN1) in the manual drive mode, the environmental map in the detectablearea AR1 of the camera 1 a including the position information of thedivision lines L1 and L2 is generated on the basis of the camera image(S2). At this time, when other vehicle 102 traveling on the oppositelane (second lane LN2) is recognized from the camera image of thesubject vehicle 101, information in a route matching section in whichthe driving route of the subject vehicle 101 and the driving route ofother vehicle 102 match, for example, information of the camera imageobtained by other vehicle 102 is acquired from other vehicle 102 (S5).That is, information obtained when other vehicle 102 travels in thepost-passing section ΔL2 from the point P2 to the point P1 andinformation obtained when other vehicle travels in the pre-passingsection ΔL1 from the point P1 to the point P0 are acquired.

As a result, even before the subject vehicle 101 actually travels on thereturn path in the manual drive mode, a return path map which is a mapof the opposite lane can be generated (S6). Therefore, the subjectvehicle 101 can travel on the return path in the self-drive mode on thebasis of the return path map. In a case where the subject vehicle 101does not travel in the self-drive mode but travels on the return pathwhile generating the environmental map of the return path in the manualdrive mode, the return path map information (S7) already stored in thememory unit 12 at the time of traveling on the outward path can be used.Therefore, it is not necessary to generate the return path map from thebeginning, and the processing load of the controller 10 can be reduced.

According to the present embodiment, following functions and effects canbe achieved.

(1) The map generation apparatus 50 includes: a vehicle recognition unit173 that recognizes other vehicle 102 traveling on an opposite lane(second lane LN2) opposite to a current lane (first lane LN1) on whichthe subject vehicle 101 travels; an information acquisition unit 175that, when other vehicle 102 is recognized by the vehicle recognitionunit 173, acquires information of an external situation around othervehicle 102 in a route matching section (pre-passing section ΔL1 andpost-passing section ΔL2) in which a driving route of the subjectvehicle 101 and a driving route of other vehicle 102 match in a drivingroute RT including the current lane and the opposite lane, obtained byother vehicle 102 traveling on the opposite lane; and a map generationunit 17 (return path map generation unit 172) that generates a map, thatis, a return path map for the opposite lane in the route matchingsection, on the basis of the information acquired by the informationacquisition unit 175 (FIGS. 2 and 3). As a result, even before thesubject vehicle 101 travels on the return path after traveling on theoutward path, the subject vehicle 101 can generate the return path mapby itself, and the map generation can be efficiently performed.

(2) The map generation apparatus 50 further includes a routedetermination unit 174 that determines whether or not there is the routematching section (FIG. 3). When it is determined by the routedetermination unit 174 that there is the route matching section, theinformation acquisition unit 175 acquires information of the externalsituation around other vehicle 102 in the route matching section (FIG.5). As a result, since the information of the external situation aroundother vehicle 102 having a high utility value for generating the returnpath map is acquired, it is possible to suppress acquisition of uselessinformation.

(3) The route matching section includes a section in which a route onwhich the subject vehicle 101 is scheduled to travel and a route onwhich other vehicle 102 has already traveled match, that is, thepost-passing section ΔL2 (FIGS. 2 and 4A). As a result, the drivingroute of the subject vehicle 101 after passing other vehicle 102 can bereliably matched with the route on which other vehicle 102 has actuallytraveled, and the reliability of the route matching in the routematching section is high.

(4) The route matching section also includes a section in which a routeon which the subject vehicle 101 has already traveled matches with aroute on which other vehicle 102 is scheduled to travel, that is, thepre-passing section ΔL1 (FIGS. 2 and 4B). As a result, it is possible toacquire information of the driving route on the return pathcorresponding to the driving route on the outward path on which thevehicle has actually traveled, and it is possible to acquire usefulinformation for generating the return path map.

(5) The map generation apparatus 50 further includes a camera 1 a thatdetects an external situation around the subject vehicle 101 (FIG. 3).The map generation unit 17 (outward path map generation unit 171)further generates a map for the current lane, that is, an outward pathmap on the basis of the external situation detected by the camera 1 a(FIG. 5). As a result, the outward path map and the return path map canbe simultaneously generated during traveling on the outward path, andthus it is possible to efficiently generate a map.

(6) The map generation apparatus 50 further includes a route settingunit (action plan generation unit 15) that sets a target route when thesubject vehicle 101 travels on the opposite lane, on the basis of themap for the opposite lane generated by the map generation unit 17 (FIG.3). This enables traveling in the self-drive mode even before travelingin the manual drive mode for generating the environmental map.

The above embodiment may be modified into various forms. Somemodifications will be described below. In the above embodiment, theexternal sensor group 1, which is an in-vehicle detection device such asthe camera 1 a, detects the external situation around the subjectvehicle 101. However, the external situation may be detected using adetection device such as a LiDAR other than the camera 1 a or adetection unit other than the in-vehicle detection device. In the aboveembodiment, the information acquisition unit 175 communicates with othervehicle 102 by inter-vehicle communication via the communication unit 7and acquires information and the like obtained by other vehicle 102.However, the map information may be acquired via a server device, andthe configuration of an information acquisition unit is not limited tothe configuration described above.

In the above embodiment, the map generated by the map generation unit 17is stored in the memory unit 12. However, the map information may betransmitted to the server device via the communication unit 7 so thatother vehicle 102 can use the map information. Alternatively, the mapinformation may be directly transmitted to other vehicle 102 via theinter-vehicle communication. In the above embodiment, the vehiclerecognition unit 173 recognizes other vehicle 102 traveling on theopposite lane, on the basis of the camera image. However, other vehiclemay be recognized on the basis of information of other detection unitssuch as a LiDAR or via communication (road-to-vehicle communication)between the communication unit installed on the road and the subjectvehicle 101 (inter-vehicle communication). Therefore, the configurationof a vehicle recognition unit is not limited to the configurationdescribed above. In the above embodiment, it is determined whether ornot there is a route matching section by recognizing the driving routeof other vehicle 102 from the image from the camera 1 a. However, it maybe determined whether or not there is the route matching section byrecognizing the driving route of other vehicle 102 from the informationobtained via the communication unit 7, and the configuration of a routedetermination unit is not limited to the configuration described above.

In the above embodiment, the map generation unit 17 generates theenvironmental map of the outward path at the current point P0 (currenttime point T0) on the basis of the camera image acquired by the camera 1a, and generates the environmental map of the return path using theinformation from other vehicle 102 acquired by the informationacquisition unit 175. However, the outward path map and the return pathmap may not be generated at the same time. When the outward path map isalready generated, the map generation unit 17 (the return path mapgeneration unit 172) may generate only the return path map on the basisof information from other vehicle 102. Therefore, the configuration of amap generation unit is not limited to the configuration described above.

In the above embodiment, the example in which the map generationapparatus is applied to the self-driving vehicle has been described.That is, the example in which the self-driving vehicle generates theenvironmental map has been described. However, the present invention canbe similarly applied to a case where a manual driving vehicle having ornot having a driving support function generates the environmental map.

The present invention can also be used as a map generation methodincluding recognizing another vehicle 102 traveling on an opposite laneLN2 opposite to a current lane LN1 on which a subject vehicle 101travels, acquiring an information of an external situation around theother vehicle in a route matching section when the other vehicle 102 isrecognized, the information of the external situation being obtained bythe other vehicle 102 traveling on the opposite lane LN2, the routematching section being a section in which a driving route of the subjectvehicle 101 and a driving route of the other vehicle 102 match in adriving route RT including the current lane LN1 and the opposite laneLN2, and generating a map for the opposite lane in the route matchingsection based on the information of the external situation acquired inthe acquiring.

The above embodiment can be combined as desired with one or more of theabove modifications. The modifications can also be combined with oneanother.

According to the present invention, a map generation can be efficientlyperformed.

Above, while the present invention has been described with reference tothe preferred embodiments thereof, it will be understood, by thoseskilled in the art, that various changes and modifications may be madethereto without departing from the scope of the appended claims.

What is claimed is:
 1. A map generation apparatus, comprising anelectronic control unit including a microprocessor and a memoryconnected to the microprocessor, wherein the microprocessor isconfigured to perform: recognizing another vehicle traveling on anopposite lane opposite to a current lane on which a subject vehicletravels; acquiring an information of an external situation around theother vehicle in a route matching section when the other vehicle isrecognized, the information of the external situation being obtained bythe other vehicle traveling on the opposite lane, the route matchingsection being a section in which a driving route of the subject vehicleand a driving route of the other vehicle match in a driving routeincluding the current lane and the opposite lane; and generating a mapfor the opposite lane in the route matching section, based on theinformation of the external situation.
 2. The map generation apparatusaccording to claim 1, wherein the microprocessor is configured tofurther perform determining whether the route matching section exists,and the microprocessor is configured to perform the acquiring includingacquiring the information of the external situation around the othervehicle in the route matching section when it is determined that theroute matching section exists.
 3. The map generation apparatus accordingto claim 2, wherein the route matching section is a section in which aroute on which the subject vehicle is scheduled to travel and a route onwhich the other vehicle has already traveled match.
 4. The mapgeneration apparatus according to claim 2, wherein the route matchingsection is a section in which a route on which the subject vehicle hasalready traveled and a route on which the other vehicle is scheduled totravel match.
 5. The map generation apparatus according to claim 1,further comprising a detection device that detects an external situationaround the subject vehicle, wherein the microprocessor is configured toperform the generating further including generating a map for thecurrent lane based on the external situation detected by the detectiondevice.
 6. The map generation apparatus according to claim 5, whereinthe microprocessor is configured to perform the generating includinggenerating the map for the opposite lane based on the information of theexternal situation around the other vehicle while generating the map forthe current lane based on the external situation detected by thedetection device.
 7. The map generation apparatus according to claim 5,wherein the opposite lane is defined by a left and right division lines,the microprocessor is configured to perform the acquiring includingacquiring information on positions of the left and right division lines,and the detection device detects one of the left and right divisionlines.
 8. The map generation apparatus according to claim 1, wherein themicroprocessor is configured to further perform setting a target routewhen the subject vehicle travels on the opposite lane, based on the mapfor the opposite lane generated.
 9. The map generation apparatusaccording to claim 8, wherein the subject vehicle is a self-drivingvehicle having a self-driving capability, and the microprocessor isconfigured to perform the setting including setting the target routeused when the subject vehicle travels on the opposite lane byself-driving.
 10. A map generation apparatus, comprising an electroniccontrol unit including a microprocessor and a memory connected to themicroprocessor, wherein the microprocessor is configured to function as:a vehicle recognition unit that recognizes another vehicle traveling onan opposite lane opposite to a current lane on which a subject vehicletravels; an information acquisition unit that acquires an information ofan external situation around the other vehicle in a route matchingsection when the other vehicle is recognized by the vehicle recognitionunit, the information of the external situation being obtained by theother vehicle traveling on the opposite lane, the route matching sectionbeing a section in which a driving route of the subject vehicle and adriving route of the other vehicle match in a driving route includingthe current lane and the opposite lane; and a map generation unit thatgenerates a map for the opposite lane in the route matching section,based on the information of the external situation acquired by theinformation acquisition unit.
 11. The map generation apparatus accordingto claim 10, wherein the microprocessor is configured to furtherfunction as a route determination unit that determines whether the routematching section exists, and the information acquisition unit acquiresthe information of the external situation around the other vehicle inthe route matching section when it is determined by the routedetermination unit that the route matching section exists.
 12. The mapgeneration apparatus according to claim 11, wherein the route matchingsection is a section in which a route on which the subject vehicle isscheduled to travel and a route on which the other vehicle has alreadytraveled match.
 13. The map generation apparatus according to claim 11,wherein the route matching section is a section in which a route onwhich the subject vehicle has already traveled and a route on which theother vehicle is scheduled to travel match.
 14. The map generationapparatus according to claim 10, further comprising a detection devicethat detects an external situation around the subject vehicle, whereinthe map generation unit further generates a map for the current lanebased on the external situation detected by the detection device. 15.The map generation apparatus according to claim 14, wherein the mapgeneration unit generates the map for the opposite lane based on theinformation acquired by the information acquisition unit whilegenerating the map for the current lane based on the external situationdetected by the detection device.
 16. The map generation apparatusaccording to claim 14, wherein the opposite lane is defined by a leftand right division lines, the information acquired by the informationacquisition unit includes information on positions of the left and rightdivision lines, and the detection device detects one of the left andright division lines.
 17. The map generation apparatus according toclaim 10, wherein the microprocessor is configured to further functionas a route setting unit that sets a target route when the subjectvehicle travels on the opposite lane, based on the map for the oppositelane generated by the map generation unit.
 18. The map generationapparatus according to claim 17, wherein the subject vehicle is aself-driving vehicle having a self-driving capability, and the routesetting unit sets the target route used when the subject vehicle travelson the opposite lane by self-driving.
 19. A map generation method,comprising recognizing another vehicle traveling on an opposite laneopposite to a current lane on which a subject vehicle travels; acquiringan information of an external situation around the other vehicle in aroute matching section when the other vehicle is recognized, theinformation of the external situation being obtained by the othervehicle traveling on the opposite lane, the route matching section beinga section in which a driving route of the subject vehicle and a drivingroute of the other vehicle match in a driving route including thecurrent lane and the opposite lane; and generating a map for theopposite lane in the route matching section, based on the information ofthe external situation acquired in the acquiring.